Other accounts included a Black Lives Matter page, one about gun rights, and another centering around dogs, which experts think was used to build a large fan base before slowly introducing political posts.

Paid posts were a part of getting their pages to grow quickly, and Facebook has turned over 3,000 Russia-linked ads to Congress. The social media giant allows publishers to narrowly target audiences with ads, including by geography, age, gender, and state interests.

“We’re obviously deeply disturbed by this,” said Joel Kaplan, Facebook vice president for United States public policy. “The ads and accounts we found appeared to amplify divisive political issues across the political spectrum.”